Hepatitis C infection occurs in one-third of all HIV-infected individuals. Liver disease has become more clinically significant among patients coinfected with HIV and HCV. Several studies have shown that coinfected individuals develop earlier and severe liver disease. Interferon with ribavirin has become the therapy of choice among people with non-genotype 1a. This is a pilot study to address the relationship of clinical response to combination therapy to the virologic and immunologic parameters. The study will also address the safety and efficacy of the peginterferon alfa-2b among HIV- infected individuals. The predictive ability of baseline HCV viral load, rate of decline of HCV viral load, HIV viral load and CD4 counts to the clinical response of chronic hepatitis to peginterferon and ribavirin will also be studied. Approximately sixty patients who are infected with both HIV and HCV and also have evidence of fibrosis will receive peginterferon alfa-2b and ribavirin for 48 weeks. In order to enroll sixty patients for this study, we will be screening a total of 180 patients. During the 72 weeks study these patients will be monitored for HCV viral load, and other HIV viral load and CD4 counts. Viral kinetics will also be monitored closely and the slope of second, slower phase decline of HCV viral load, which corresponds to the rate of infected cell death presumably may lead to sustained hepatitis C virologic response. The results of the study will enable us to better delineate the possible predictors of sustained response to peginterferon and ribavirin. The safety and tolerability of a combination therapy with peginterferon and ribavirin among HIV-infected individuals on antiretroviral therapy will further define the standard therapy of chronic hepatitis C in HIV-infected individuals.